1. Field of the Invention
The present invention is directed to a method of treating Epstein-Barr virus infection and to the discovery that a mammalian liver extract that is efficacious in treating such diseases. The present invention is also directed to a method of treating such diseases with this same mammalian liver extract and/or with polypeptides shown in Sequence identification numbers 1-9.
2. Description of the Prior Art
Epstein-Barr virus is an oncogenic virus. This virus is known to cause mononucleosis, nasopharyngeal cancer, Burkitt's lymphoma, Hodgkin's disease and X-linked lymphoproliferation. Currently, Epstein-Barr virus infection is treated with Acyclovir. In order, however, to obtain anti-EBV viral activity a very high dosage to produce a concentration of 2.0 .mu.g/ml must be given. This dosage, however, in humans is not effective, because Acyclovir often crystallizes in the kidneys at this dose.
Mammalian liver extract has been used for the treatment of a wide range of infectious and noninfectious dermatologic conditions, including ache vulgaris, Journal Invest Dermatology, 2:205-218 (1939); first and second degree burns, Mississippi Valley Medical Journey, 76:199 (1954); sunburn, Clinical Medicine, 3:245 (1956); poison ivy dermatitis, Clin. Med., 3:425 (1956) and Herpes zoster, Southern Medical Journal, 50:1524 (1957). The active principle and mechanism have not been described. Although some medical practitioners have used liver extract for the treatment of dermatologic conditions, it is not regarded as an antiviral or immune modulator agent even for skin therapy.
Mammalian liver extract has been reported to have bradykinin potentiating activity. Tewksbury et al., Arch. Blochem. Biophys. (U.S.), 112, 453 (1965); Tewksbury, Archives Int'l. de Pharmacodynamie et de Therapie, 173, 426 (1968); Tewksbury, Dissertation Abstracts International-Part II, Vol. 25/04, p. 2214 (1964). Further, one commercially-available liver extract (sold under the trademark KUTAPRESSIN by Kremers-Urban Co., Milwaukee, Wisconsin) exerts its action, according to product literature, only with respect to tissues that have been injured and when inflammation and edema are present.
In U.S. Pat. No. 5,055,296, the use of a heat stable acetone-insoluble, water-soluble mammalian liver extract was shown to be effective in the treatment of mammals infected with nondermatologic viruses, in particular, in the treatment of chronic fatigue syndrome. Thus, with this background, the inventors endeavored to discover a method to treat Epstein-Bart virus infection.